The technical field is antiballistic materials and armored panels constructed therefrom. The technical field also includes construction techniques incorporating armored panels in vehicles and other structures.
Many forms of antiballistic materials and barriers are available. Such materials are classified according to their ability to deter ballistic attacks. Underwriters Laboratories (UL) Standard for Safety for Bullet-Resisting Equipment (i.e., UL-752 requirements) covers materials, devices, and fixtures used to form bullet-resisting barriers that protect against robbery or holdup. The term “bullet-resisting” generally signifies that protection is provided against complete penetration, passage of fragments of projectiles, or spalling (i.e., fragmentation of the protective material) to the degree that injury would be caused to a person standing directly behind the bullet-resisting barrier.
The UL-752 requirements are classified according to levels, beginning at Level 1. Higher UL levels provide greater protection against projectiles. However, greater protection against ballistic attack typically requires heavier and larger ballistic materials. When the object to be protected is a building, the total weight of any antiballistic shielding is limited by the ability of the building to support the additional weight of the shielding. For example, conventional shielding for buildings and other structures involves adding concrete or steel layers to the building walls. These layers of shielding material add considerable weight to buildings and other structures. In particular, due to this added weight, conventional shielding materials may not be suitable for taller buildings and other structures. Additionally, conventional shielding materials, such as steel, are costly. Moreover, mobile objects requiring antiballistic shielding are similarly subject to the same or even more stringent weight and cost limitations.